The present invention pertains to a technical field where image input apparatuss are utilized for digital photoprinters for photoelectrically reading images recorded on films to obtain prints (photographs) that have been reproduced from the images.
Images recorded on photographic films (hereinafter called the films) such as negative films, reversal films and the like are mainly printed out on photosensitive material (photographic paper) now by projecting the on-film image onto the photosensitive material so that the photosensitive material is subjected to surface exposure or so-called direct exposure (analog exposure).
On the other hand, printing apparatus utilizing digital exposure have been put to practical use in recent years; more specifically, a digital photoprinter is used for printing out (finishing off) an image recorded on a film through the steps of photoelectrically reading the image, converting the read-out image into a digital signal, performing various sorts of image processing in order to obtain image data to be recorded and subjecting photosensitive material to scanning exposure by means of the recording light modulated according to the image data, whereby to record the image (latent image).
As exposure conditions at the time of printing can be determined by processing images with digital data as image data in the digital photoprinter, high-grade prints that have been unavailable until now become obtainable by making compensation for image fade-out and improper gradation such as, washed-out highlight and dull shadow originating from backlight, electronic flashing and the like, sharpness processing, compensation for color or density failure and so forth. Moreover, a composite photograph using a plurality of images, image division, a composition of characters and the like can be attained by processing the image data, which makes it possible to output edited/processed prints freely according to intended uses.
Furthermore, the digital photoprinter makes image data utilizable for various purposes other than photography because it allows output images as prints (photographs) and also allows the image data to be not only supplied to a computer, for example, but also stored in optical and/or magnetic recording media such as floppy disks and so on.
Such a digital photoprinter as described above essentially comprises an image input apparatus having a scanner (image reading apparatus) for photoelectrically reading an image recorded on a film and an image processing apparatus for subjecting the read-out image to image processing in order to provide output image data (exposure conditions), and an image output apparatus having a printer (image recording apparatus) for recording a latent image by subjecting photosensitive material to scanning exposure according to the image data outputted from the image input apparatus and a processor (developing apparatus) for subjecting the exposed photosensitive material to developing processing for printing purposes.
The operation of the scanner includes making read light emitted from a light source incident on a film to obtain projected light for carrying an image projected on the film, effecting image formation in an image sensor such as a charge coupled device (CCD) by means of an image forming lens so as to read the image by subjecting the projected light to photoelectric conversion, performing various kinds of image processing as occasion demands and sending data concerning the on-film image (image data signal) to the image processing apparatus.
The operation of the image processing apparatus includes setting image processing conditions according to the image data read by the scanner, applying image processing corresponding to the set conditions to the image data and sending output image recording data (exposure conditions) to the printer.
The operation of the printer, that is, a printer utilizing light beam scanning exposure, for example, includes modulating a light beam according to the image data sent from the image processing apparatus, deflecting the light beam in the main scanning direction, transporting the photosensitive material in a auxiliary scanning direction perpendicular to the main scanning direction in order to form a latent image by exposing (printing) the photosensitive material, using the light beam that carries the image therewith and performing developing processing corresponding to the photosensitive material in the processor in order to make a print (photograph) reproduced from the on-film image.
When an image is photoelectrically read by the image input apparatus in the digital photoprinter, pre-scanning (pre-reading) for reading an original with low resolution is usually carried out prior to image reading (main reading, that is, main scanning) for obtaining output image data and the image data obtained from the pre-scanning is used for setting read conditions for the main scanning and (image) processing conditions for acquiring the output image data by processing the image data obtained from the main scanning.
Moreover, the processing conditions are appropriately adjusted by an operator who examines the conditions as the need arises.
The read conditions at the time of the main scanning are set from the image data obtained from the pre-scanning so that the output of the image sensor such as a CCD is not saturated but equivalent to the minimum possible quantity of light with the lowest density of the original image; more specifically, the quantity of read light (adjusted stopping value), the accumulatable time of the CCD sensor and the like are set to accomplish the aforesaid conditions.
Thus, the whole density range of the original image can be read in the widest dynamic range.
However, because the scanner is restricted by the dynamic range, the S/N ratio and the like, the read conditions at the time of the main scanning like this make photographic conditions unfavorable and when the dynamic range of density of the on-film image is wide, a print embodying a high-quality image may not be reproduced even though the image data obtained from the main scanning is properly processed.
For example, the primary object (normally, the face of a person) in a print is required to be appropriately finished and even in a case where photographic conditions are bad because of shooting a backlight scene or a scene with electronic flashing, priority is given to a face other than the rest of the image reproduced in print and the face is suitably processed in order that it is finished without being faded out.
In the above case, therefore, the image processing conditions (density compensating conditions) are set in such a manner as to suitably finish a high- or a low-density portion in proportion to the density of the face of the person taken on the film. However, the face in the print reproduced from the image looks sandy though the image processing is used to prevent the face from being faded out by adjusting the density thereof. In extreme cases, an unsuitable print is reproduced and even when such an unsuitable print is not reproduced, a high-quality image is never reproduced.
An object of the present invention intended to solve the foregoing problems in the prior art is to provide an image input apparatus for furnishing output image data by carrying out pre-scanning and main scanning in order to photoelectrically read an on-film image, which image input apparatus is capable of stably outputting a high-quality image by reading the on-film image even though photographic conditions are bad because of shooting a backlight scene or a scene with electronic flashing and even though the image has a wide dynamic range of density.
In order to solve the foregoing problems, an image input apparatus for photoelectrically reading an image and applying predetermined image processing to image data obtained so as to provide output image data according to the present invention comprises pre-reading means for reading the image before main reading is carried out to obtain the output image data, processing condition setting means for setting image processing conditions according to the image data obtained from the pre-reading, display means for processing the image data obtained from the pre-reading according to the image processing conditions set by the processing-condition setting means and displaying the processed image data, adjusting means for designating the adjustment of the image processing conditions set by the processing-condition setting means after the image is displayed on the display means, read-condition determining means for determining main read conditions according to the image data obtained from the pre-reading and the designation of the adjustment of the image processing conditions specified by the adjusting means, means for definitely deciding the image processing conditions, and designating means for designating the commencement of the main reading.
Furthermore, it is preferred that the read means for photoelectrically reading the original image is a CCD sensor; the designation of the adjustment of the image processing conditions to be reflected in the main read conditions determined by the read-condition determining means is concerned with the adjustment of the density and the tinting; and the read conditions affected by the adjustment signify at least one of the adjustment of the quantity of light and the accumulatable time of the CCD sensor.